/*
 * Copyright 2009 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.zxing.multi.qrcode.detector;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import com.google.zxing.DecodeHintType;
import com.google.zxing.NotFoundException;
import com.google.zxing.ReaderException;
import com.google.zxing.ResultPointCallback;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.DetectorResult;
import com.google.zxing.qrcode.detector.Detector;
import com.google.zxing.qrcode.detector.FinderPatternInfo;

/**
 * <p>Encapsulates logic that can detect one or more QR Codes in an image, even if the QR Code
 * is rotated or skewed, or partially obscured.</p>
 *
 * @author Sean Owen
 * @author Hannes Erven
 */
public final class MultiDetector extends Detector {

    private static final DetectorResult[] EMPTY_DETECTOR_RESULTS = new DetectorResult[0];

    public MultiDetector(BitMatrix image) {
        super(image);
    }

    public DetectorResult[] detectMulti(Map<DecodeHintType, ?> hints) throws NotFoundException {
        BitMatrix image = getImage();
        ResultPointCallback resultPointCallback =
                hints == null ? null : (ResultPointCallback) hints.get(DecodeHintType.NEED_RESULT_POINT_CALLBACK);
        MultiFinderPatternFinder finder = new MultiFinderPatternFinder(image, resultPointCallback);
        FinderPatternInfo[] infos = finder.findMulti(hints);

        if (infos.length == 0) {
            throw NotFoundException.getNotFoundInstance();
        }

        List<DetectorResult> result = new ArrayList<>();
        for (FinderPatternInfo info : infos) {
            try {
                result.add(processFinderPatternInfo(info));
            } catch (ReaderException e) {
                // ignore
            }
        }
        if (result.isEmpty()) {
            return EMPTY_DETECTOR_RESULTS;
        } else {
            return result.toArray(new DetectorResult[result.size()]);
        }
    }

}
